What it is

Code Crack is the Mastermind family of games, distilled to its essential rules. The computer picks a four-position code from five colours, repeats allowed. You make a guess. The computer tells you (without revealing which positions are which): how many pegs in your guess are correct colour and correct position; how many are correct colour but wrong position. You make another guess, informed by what you just learned. Ten guesses total. Crack it before you run out.

How to play

Tap a colour in the palette to fill the next empty slot in your current guess.
Tap a peg in your guess to remove it.
Submit your guess when all four slots are filled.
Read the hints. Black dots = right colour, right slot. Red dots = right colour, wrong slot. Order of dots is random; they don't tell you which peg is which.
Win or lose. Crack the code in ten guesses → win counter +1. Run out → the code is revealed.

The trick

New players guess randomly until they get lucky. Better players use their first guess to fingerprint colour presence. A canonical opener is red, red, blue, blue — it instantly tells you how many of those two colours are in the code. Your second guess then introduces two new colours: green, green, gold, gold. Together those two guesses categorise the entire palette: every code is now reduced to a permutation of four colours from a known multiset. The third guess starts placing them. With this technique, a typical code falls in five to seven guesses.

What this scored well on

Pure deduction. No randomness in feedback. No "lucky breaks". Every win is the result of reasoning.
The hint UI. Black dots and red dots, both visually clear and high-contrast against the pegs. We tried numbers and it felt like a spreadsheet; we tried positional reveals and it broke the game.
Replayability through palette size. Five colours over four positions gives 625 possible codes — enough variety that experienced players never get the same code twice in a session, but small enough that perfect play caps at five guesses.

What it gets wrong

Code Crack doesn't track time. We considered a chess-clock variant but decided against it; the game's whole pleasure is the unhurried "okay, now what does this rule out?" interior moment. Speed-running this game would be a different game. If we add a time-attack mode, it'll be in a separate variant page.

Who it's for

Code Crack is for people who enjoyed the original Mastermind set on a coffee table at someone's grandparents' house. It's also a textbook teaching aid for elementary information-theory ideas — every guess is a literal binary query against a possibility space.

Where we'd point you next

If you liked the deduction rhythm, try Maze Spin (#08 — planning ahead). If you liked the colour palette, watch for Sound Match (#12 — audio memory pairs) shipping in this batch.

Released · 12 May 2026 · Editor's score 4.1 / 5 · Reviewed by Bill